The invention is based on an angle grinder as generically defined by the preamble to claim 1.
An angle grinder with such a housing is known from German Patent Disclosure DE 43 44 128. The housing in this case is in one piece and is screwed onto a cup-shaped motor housing. A spindle bearing receptacle in which the bearing for a work spindle is received is embodied integrally with the housing. For changing a tool that is mounted on the work spindle, the work spindle has to be fixed. This is done by providing that a spindle lock, by means of a hand lever and counter to the force of a restoring spring, presses a detent cam into an indentation that is embodied on a clamping flange, which in turn is connected to the work spindle in such a way that it rotates with it. In the operation of the work spindle and when the tool secured to it is changed, major forces, or clamping forces, occur. It is therefore necessary that both the spindle bearing receptacle and the locking device comprise a high-quality, wear-resistant material. Since the spindle bearing receptacle is embodied integrally with the housing, the entire housing must be made from such a high-quality, expensive material.
The angle grinder of the invention as defined by the characteristics of claim 1 has the advantage over the prior art that the entire housing can be made by shell construction and can be fabricated from an economical material; only the insert part to be inserted separately into the housing has to comprise especially high-quality material. The possibility is thus afforded of producing a less expensive product than was previously possible. This is made possible by the fact that the entire housing is made of shell construction, that is, with a mounting shell and a cap shell, between which the insert part is inserted. Because the insert part is fixed with its first and second fixation device between the mounting shell and the cap shell, the spindle bearing receptacle and the spindle locking receptacle, also disposed in the insert part, always remain stationary in their position relative to the housing.
It is advantageous if the spindle bearing receptacle and the spindle locking receptacle are disposed parallel to one another in a base body of the insert part, and if this base body has an aperture oriented perpendicular to the spindle locking receptacle, which is embodied as a through hole. As a result, it is possible for the insert part to be well fixed in its position between the mounting shell and the cap shell, each of which have a screw dome that is disposed in a line with the through hole.
It is also advantageous if the insert part has an outrigger, on which a first fixation device is disposed, the cross section of the outrigger being in the form of a double T. The first fixation means of the mounting shell and second fixation means of the cap shell can easily engage the resultant indentations on both sides of the outrigger, thus assuring good fixation of the angular position of the insert part in the housing between the two shells.
It is also advantageous if the insert part comprises a high-quality, wear-resistant material, while conversely the mounting shell and the cap shell are of an inexpensive material. This is made possible because only the spindle bearing receptacle and the spindle locking bolt experience heavy loads, while the remaining points of the housing experience hardly any load. As material for the insert part, Grivory or a similar material is used. This is a glass-fiber-reinforced, heavy-duty polyamide plastic, such as PA 6-66 GF.
An advantageous fixation of the insert part in the housing is achieved by the provision that the outrigger of the insert part rests over a large surface area on first and second bearing faces of the mounting shell and cap shell, respectively.
Advantageously, in the region of its through hole, the insert part has first and second centering devices, oriented toward each of the screw domes, that can be brought into engagement with first and second centering means of the screw domes. As a result, centering and thus correct insertion of the insert part between the mounting shell and the cap shell are assured.
Further advantageous features of the invention will become apparent from the other dependent claims.